1. Field of the Invention
The present invention relates generally to the field of dental appliances. More specifically, the present invention discloses an apparatus for maintaining a dry field during dental procedures.
2. Statement of the Problem
Throughout the field of dentistry, chairside procedures must be managed to simultaneously achieve a number of objectives. Dentists, orthodontists, prosthodontists, oral surgeons and the like must provide patient comfort while at the same time accomplishing complex therapeutic treatment procedures within the confines of the oral cavity. The clinician must also manage a number of peripheral factors while he or she focuses on achieving worthwhile, long-lasting treatment results. The clinician must strive to minimize such factors as the amount of chair time required to accomplish various treatment goals, the amount of auxiliary staff assistance required as well as overall practice overhead to insure that such professional services remain economically practical for all involved. All of these factors drive dental professionals to embrace improved chairside systems, armamentarium, techniques and procedures that save time, improve results and reduce costs. One aspect of such dental practice economics addressed by the present invention involves those procedures where the polymerization or curing of dental acrylic and various types of dental adhesives must be accomplished. Such procedures typically demand that a dry field be achieved and maintained from the beginning to the end of such procedures. Establishing a dry field involves the isolation of a tooth or a segment a dental arch where tooth surfaces must be cleaned, desiccated, and kept completely dry for the duration of a procedure. In such cases, maintaining dry conditions within the oral environment is essential for the successful, long-term functioning of such cured resins and polymers.
Since tooth enamel and dentin cannot be dissolved by organic solvents, commonly used dental resins and polymers rely on a mechanical bond rather than a chemical bond for adhering such things as orthodontic braces, dental appliances, veneers and sealants, reconstructive prosthesis and composite restorations. Many common bonding procedures involve the preparative step of etching the prepared tooth surfaces with an orthophosphoric or citric acid solution to create a roughened tooth bonding surface. Similarly, it is a common practice to roughen metallic bonding surfaces of various types of dental hardware through a process of vapor abrasion. Vapor abrasion involves directing compressed air carrying micron-sized particles of ceramic carbide or silicon dioxide. Both etching and vapor abrasion prepare the bonding substrates to create greater surface area and greater “purchase” for improved strength and retention of the subsequently-applied adhesive.
Saliva and saliva-borne oral biotica are the nemesis of sound mechanical bonds in that if present, they introduce a release agent of sorts, disrupting the micro inter-articulation of the adhesive with the prepared substrates to be joined. Likewise, for other types of dental polymers such as dental acrylic, moisture serves as an inhibiter of full molecular cross-linking and interferes with the attainment of a complete, amorphous chemical cure throughout the acrylic mass. In such cases where less than complete polymerization is achieved, toxic, unpolymerized monomer may leach into the oral environment. Further, unless a full cure is achieved, such materials do not achieve full strength or full hardness. As can be appreciated, achieving and maintaining a dry field is a critical, yet routine and sequential step required by many types of dental procedures.
As an example of a typical chairside procedure requiring a dry field, U.S. Pat. No. 6,354,833 (Townsend-Hansen) describes the need to maintain dry field conditions while bonding orthodontic brackets to a patient's teeth. The composite resins used for bonding brackets to the exposed tooth surface typically require a completely dry field of operation from start to finish. The enamel is etched at the bond site leaving a roughened surface suitable for resin infiltration. A primer is placed on the etched enamel surface, and the bonding resin is placed on the bracket. The bracket is then positioned on the tooth and allowed to cure chemically or is cured by light irradiation from a dental curing device. In orthodontics, it is well known that saliva contamination of a prepared bonding site will reduce the ultimate strength attained by the cured bonding material and it will significantly increase the likelihood of problematic bracket bond failures during orthodontic treatment.
Saliva is produced in and secreted from the salivary glands. The basic secretory units of salivary glands are clusters of cells called an acini. These cells secrete a fluid that contains water, electrolytes, mucus and enzymes, all of which flow out of the acinus into collecting ducts. Secretion of saliva is under control of the autonomic nervous system, which controls both the volume and type of saliva secreted. The production of saliva is a naturally-occurring continuous process that cannot be temporarily halted or consciously regulated. One aspect then of the many chairside procedures that require a dry field is that the need to evacuate saliva from the mouth is continuous as it collects and puddles in the lower posterior vestibules and under the tongue.
In the dental operatory, the responsibility for removing saliva from a patient's mouth is typically relegated to auxiliary staff personnel, who must periodically manipulate, reposition and activate saliva suction/removal devices. In practice, the actual evacuation of pooled saliva periodically requires a few seconds at each of multiple positions in the mouth. This typical chairside scenario introduces a number of obstacles and limitations for the attending clinician in his or her efforts to achieve treatment-related goals. First, the attending clinician must periodically pause from his or her in-process procedure while saliva is evacuated. This results in an interruption to the clinician's visual and mental focus. The very presence of a second person at chairside alters the ergonomics of the dental operatory and restricts space and free movement. The auxiliary staff member must move their hands in and around the oral cavity to evacuate saliva, again breaking the clinician's field of view, as well as mental focus. The cost associated with the presence of an auxiliary staff member, as well as the cumulative increase in time required for saliva evacuation all combine to increase the overhead costs for the practice, which increases the ultimate cost of treatment. For all of these reasons, the value of improved dry field-related devices and methods can be appreciated and for all of these reasons, improved devices and methods for the removal of saliva have been sought.
In addition to the challenges of saliva control, another fundamental challenge faced by clinicians involves the increased difficulty of performing procedures in the posterior region of the oral cavity. The central problem associated with delivering dental treatment in this region of the mouth is the general restriction of space as well as reduced physical and visual access. The posterior regions of the mouth are inherently darker and less accessible and it is more difficult to direct light where needed. The adjacent bony structures of the anterior aspect of the ramus, and the soft tissue and musculature of the cheeks restrict the clinician's access and prevent a direct or perpendicular line of sight. The confined vestibular space between the buccal surfaces of the posterior teeth and the adjacent soft tissues of the cheeks limits the number and size of dental instruments that can occupy the space, and makes the transportation of dental materials and dental armamentarium in and out of the mouth more difficult.
Yet another challenge routinely faced by the clinician is the interference and unpredictability posed by a free and unruly tongue. Patients typically have little positional awareness of their tongue during treatment, and wide and unpredictable tongue movements can suddenly interfere with the clinician's efforts and focus, and a wandering tongue can potentially contaminate dry field conditions.
Prior Art. The prior art in the field of dentistry and orthodontics includes a wide variety of tongue retractors and devices for extracting saliva, including the following:
InventorPatent No.Issue DateConfresi3,049,806Aug. 21, 1962Schroer3,916,880Nov. 4, 1975Reichley4,215,984Aug. 5, 1980Nelson4,259,067Mar. 31, 1981O'Neil4,260,378Apr. 7, 1981Moore4,354,837Oct. 19, 1982Diamond4,511,329Apr. 16, 1985Dyfvermark4,975,057Dec. 4, 1990Hickham5,037,298Aug. 6, 1991Duggan et al.5,152,686Oct. 6, 1992Anderson5,460,524Oct. 24, 1995“DentaPops”, New Line Medical - Dental and Medical Products, http://www.newlinemedical.com/DentaPops.html
Anderson discloses a device and method for saliva suction in dental procedures that includes a tongue retractor and bite handle. The embodiment shown in FIG. 12 of the Anderson patent includes a retraction wing or cheek retractor. This device engages the tubing in a manner that directs the suction tubing outward and in contact with the cheeks, thus holding the cheeks away from the teeth.
Confresi discloses a device for suctioning saliva from the oral cavity including a tubular member having inlet orifices on both sides of the teeth and an adjustable brace serving as a tongue depressor.
Reichley discloses a dental suction device having a U-shaped base designed to be positioned on the patient's lower teeth.
Nelson discloses a dental device for isolating a region of the mouth, and includes a frame to retain the device and a shield member to retract the tongue from the lower teeth.
O'Neil discloses a self-stabilizing intra-oral saliva evacuator.
Diamond discloses a moisture-controlling lingual dental mirror.
Dyfvermark discloses a bite block appliance with an aperture serving as an evacuation nozzle for saliva suction.
Hickham discloses an apparatus for ejecting saliva that includes a pair of saliva ejectors connected to a tongue retractor, a cheek retractor connected to a tongue retractor, and a cheek retractor connected to a tongue retainer that is secured to the tongue retractor.
Duggan et al. disclose an appliance for suctioning debris from the oral cavity that includes a tongue stabilizer and a removable suction tube secured to a bite block.
Schroer discloses a device for holding upon the mouth during dental treatment. The device includes lip retractors interconnected by a U-shaped stirrup.
Moore discloses a dental appliance having a collar with a blade-like protrusion and a locking finger for engaging a slofted groove on the cap of a saliva ejector.
The “DentaPops” internet web site discloses a disposable device resembling a candy sucker having a hollow stem for evacuating saliva.
Solution to the Problem. The present invention brings forth a multi-function device that is designed to control, and continuously remove saliva from the mouth without the need for manipulation. It is intended to be used in conjunction with conventional chairside saliva evacuation systems, and is intended to act continuously, thus greatly reducing or eliminating the need for monitoring and manipulation of saliva evacuation equipment. In particular, the cheek distention arms, webbing and lower paddles of the device serve to support the soft tissue inside the cheeks to open the patient's vestibules. The device also includes stanchions and lip retractors with vertical guides aligned to guide insertion of a suction tubes into the vestibules. In addition, the tongue shield control the tongue and create space in, and access to the posterior regions of the mouth.